Cool pavements for urban heat island mitigation: A synthetic review

Urban heat island (UHI) effect poses great challenges to urban environmental quality, building energy consumption, and public health. Over decades, research efforts have been made to develop and evaluate different UHI mitigation strategies. Governments, organizations, and commercial companies have also been working to develop building codes, standards, and green rating systems to improve energy efficiency and urban sustainability. However, a lack of synergies between the research community, governments, organizations, and commercial companies may create knowledge gaps that can become a considerable obstacle to the implementation and effectiveness of UHI mitigation strategies. This study aims to synthetically review recent research advances, building codes and green rating systems, and urban implementation projects related to the use of cool pavements for UHI mitigation. In particular, we review efforts on reflective pavements, permeable pavements, and other innovative pavement strategies. Based on this synthetic review, we identify six gaps in existing cool pavement research and five gaps related to the implementation of cool pavements in building codes, standards, and municipal projects. We further provide recommendations and suggestions for each gap. Further efforts are needed to bridge these gaps, which will be critical to proactively coping with the negative impacts of the UHI effect and promoting more sustainable urban energy use.